Achievements & Publications

The Formation of Population III Binaries

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Saigo, Kazuya,   Matsumoto, Tomoaki,   Umemura, Masayuki

We explore the possibility for the formation of Population III binaries. The collapse of a rotating cylinder is simulated with a three- dimensional, high-resolution nested grid, assuming the thermal history of primordial gas. The simulations are done with dimensionless units, and the results are applicable to low-mass as well as...

Gas stripping by radiation drag from an interstellar cloud

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Sato, Jun'ichi,   Umemura, Masayuki,   Sawada, Keisuke,   Matsuyama, Shingo

We perform two-dimensional hydrodynamic simulation of gas stripping by radiation drag from interstellar clouds moving in uniform radiation fields. To include relativistic radiation drag properly, the radiation hydrodynamic equation is solved taking into account the dilution of radiation fields by the optical depth of the cloud. As a result, it...

A Strong Ly\ensuremathα Emitter at z = 6.33 in the Subaru Deep Field Selected as an i'-Dropout

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Nagao, T.,   Taniguchi, Y.,   Kashikawa, N.,   Kodaira, K.,   Kaifu, N.,   Ando, H.

We report on the discovery of a star-forming galaxy at z=6.33 in the Subaru Deep Field. This object is selected as a candidate of an i$^′$-dropout high-redshift galaxy around z=6 because of its red i$^′$-z$^′$ color in our deep optical imaging survey in the Subaru Deep Field. Our follow-up optical...

The Effects of Early Cosmic Reionization on the Substructure Problem in Galactic Halos

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Susa, Hajime,   Umemura, Masayuki

Recent observations of the cosmic microwave background by the Wilkinson Microwave Anisotropy Probe strongly suggest that the reionization of the universe took place quite early (zåisebox-0.5ex~17). On the other hand, it has been pointed out that the cold dark matter cosmology suffers from a substructure problem in which more subgalactic...

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The Formation of Population III Binaries

Saigo, Kazuya,   Matsumoto, Tomoaki,   Umemura, Masayuki

We explore the possibility for the formation of Population III binaries. The collapse of a rotating cylinder is simulated with a three- dimensional, high-resolution nested grid, assuming the thermal history of primordial gas. The simulations are done with dimensionless units, and the results are applicable to low-mass as well as...

November 2004   The Astrophysical Journal Letters
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Gas stripping by radiation drag from an interstellar cloud

Sato, Jun'ichi,   Umemura, Masayuki,   Sawada, Keisuke,   Matsuyama, Shingo

We perform two-dimensional hydrodynamic simulation of gas stripping by radiation drag from interstellar clouds moving in uniform radiation fields. To include relativistic radiation drag properly, the radiation hydrodynamic equation is solved taking into account the dilution of radiation fields by the optical depth of the cloud. As a result, it...

October 2004   Monthly Notices of the Royal Astronomical Society
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A Strong Ly\ensuremathα Emitter at z = 6.33 in the Subaru Deep Field Selected as an i'-Dropout

Nagao, T.,   Taniguchi, Y.,   Kashikawa, N.,   Kodaira, K.,   Kaifu, N.,   Ando, H.

We report on the discovery of a star-forming galaxy at z=6.33 in the Subaru Deep Field. This object is selected as a candidate of an i$^′$-dropout high-redshift galaxy around z=6 because of its red i$^′$-z$^′$ color in our deep optical imaging survey in the Subaru Deep Field. Our follow-up optical...

September 2004   The Astrophysical Journal Letters
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The Effects of Early Cosmic Reionization on the Substructure Problem in Galactic Halos

Susa, Hajime,   Umemura, Masayuki

Recent observations of the cosmic microwave background by the Wilkinson Microwave Anisotropy Probe strongly suggest that the reionization of the universe took place quite early (zåisebox-0.5ex~17). On the other hand, it has been pointed out that the cold dark matter cosmology suffers from a substructure problem in which more subgalactic...

July 2004   The Astrophysical Journal Letters